Figure 3.

Three Mechanisms of MT-Induced Membrane Tube Formation

(A and C) Time-lapse images of a membrane tube (red arrowheads) sliding along a MT (dashed yellow line) (A) or moving together with the plus end of a growing MT (C) (white arrowheads) in the presence of 200 nM mCherry-EB3 (A), 50 nM mCherry-EB3 (C), and 15 nM His-GFP-MTLS. See also Figures S4A, S4C, S4D, S4F, and S4G and Videos S3, S4, and S6.

(B) Kymograph of a membrane tube sliding along a MT and catching up with the MT tip (green arrowhead).

(D) Growth rate of free MTs and MTs in contact with a membrane; n, from left to right: 63, 41, 179, 40, 41, and 67.

(E) Time-lapse images of a membrane tube (red arrowhead) attached to the plus end of a depolymerizing MT (white arrowhead) (dTAC) in the presence of 15 nM His-GFP-MTLS without mCherry-EB3. See also Figure S4E and Video S5.

(F) Shortening rate of free MTs and MTs pulling a membrane; n, from left to right: 36, 41, 58, and 73.

(G) A scheme of a kymograph showing membrane deformation by a dynamic MT and membrane detachment from the tip.

(H) Probability of successful membrane tube generation events occurring through different mechanisms, determined by dividing the number of observed tubes by the total number n of MT-membrane contacts that could potentially support a specific event. Numbers of events and experiments, from left to right, 48 (7), 36 (5), 50 (5), 68 (9), 6 (5), 30 (5), 37 (3), 20 (3), and 41 (3).

(I) Snapshots of a video showing a membrane tube (red arrowheads) detaching from a MT tip (white arrowheads).

(J) Probability of detachment events from a MT tip. n number of experiments (number of events), from left to right: 7 (50), 9 (68), and 3 (37).